Data transmission method adapted to network system for broadcasting distribution of streaming contents

Abstract

A data transmission method adapted to a network system for interconnecting a server with a receiver terminal via the Internet, in which a plurality of frames f(1), f(2), . . . , and f(u) are extracted from streaming contents and are distributed to a plurality of packets p(1), p(2), . . . , and p(u) by interleaving, wherein a plurality of data included in the frame f(u) represented by a matrix of m×n are distributed to a plurality of packets p(u) to p(k+u−1) (where ‘u’ and ‘k’ designate integers), whereby any one of the packets includes first data of each frame, so that it is possible to start reproducing the streaming contents after completely receiving last data of each frame without discarding packets. This noticeably reduces a time lag between the reception start timing and the reproduction start timing.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention relates to data transmission methods adapted to network systems in which streaming contents such as audio data are subjected to broadcasting distribution via networks such as the Internet. [0003] This application claims priority on Japanese Patent Application No. 2004-134115, the content of which is incorporated herein by reference. [0004] 2. Description of the Related Art [0005] Recently, various types of Internet broadcasting systems have been developed and put into practical uses as disclosed in Japanese Patent Application Publication No. 2002-202950, which teaches an Internet broadcasting station system. In streaming contents distribution on the Internet, reproduction of streaming contents may be broken due to burst error caused by the lack or loss of packets, wherein sound is unexpectedly skipped without being reproduced. In order to avoid the occurrence of the aforementioned event, interleaving ...

AI Technical Summary

Benefits of technology

[0009] It is an object of the invention to provide a data transmission method that can reduce a time lag between the reception start timing and the reproduction start timing in streaming contents broadcasting distribution using networks.

[0016] Due to the aforementioned interleaving method, any packet includes first data of a prescribed frame, whereby upon completion of reception of the last packet including last data of a prescribed frame, it is possible to start reproducing streaming data (e.g., audio contents). Thus, even when reception is started with a prescribed packet, it is possible to start reproducing a prescribed frame whose first data is allocated to the prescribed packet without discarding packets sequentially received by the receiver terminal; hence, it is possible to reduce a time lag (or a wait time) between the reception start timing (for receiving packets representing streaming contents) and the reproduction start timing.

[0020] When frame data are distributed to packets, they are changed in order, wherein even when a plurality of packets are consecutively lost during transmission, the receiver terminal restores the corresponding frame data with a random error, which improves the resistance against the lack of frames.

[0022] A plurality of data included in frames are subjected to distribution along lines of matrices of packets, wherein consecutive data aligned in the same column of the matrix of a frame are each distributed to packets with a difference b therebetween. When such a distribution difference b is reduced as b<m (where ‘m’ designates the number of lines included in each matrix), it is possible to reduce the range of packets, to which a plurality of data included in each frame are distributed, without reducing error resistance in transmission. Hence, it is possible to reduce a time lag between the reception start timing (for receiving packets) and the reproduction start timing.

[0023] As a result, even when the receiver terminal starts receiving any one of the packets, which are sequentially transmitted thereto and to which a plurality of frame data are distributed by way of interleaving, it is possible to start restoring original frame data (or to start reproducing streaming contents) within a very short time lag without discarding packets received thereby.

Problems solved by technology

In streaming contents distribution on the Internet, reproduction of streaming contents may be broken due to burst error caused by the lack or loss of packets, wherein sound is unexpectedly skipped without being reproduced.

That is, a plurality of packets are transmitted by way of a plurality of frames, wherein even when one packet is lost in transmission, a burst error may not occur in streaming data; in other words, a random error may occur in each frame.

When packets are lost in transmission, the interleaving system changes the order of sequential streaming data so as to restore original frames, so that a burst error is displaced with a random error.

This requires a relatively long time (e.g., ten seconds or more) between the reception start timing and the reproduction start timing.

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